L8

• On the day of a bull sale, how a bull looks depends on his genotype and the environment
• You can make him bigger by feeding him preferentially, but this is not passed on to his progeny
• Most registered cattle in NZ are evaluated using Breedplan Estimated Breeding Values (EBV's)

  
• EBV


  A prediction of the GENETIC VALUE of an animal for that trait eg. 400-day weight
• Selection criteria


  Easily measured, Measurable before selection decisions are made, Heritable
• Selection criteria may include

  • Breed
  • Bull stud
  • Coat colour, horns, conformation
  • Live weight, liveweight gain
  • Ultrasound measurements
  • Pedigree, show performance
  • GGT (facial eczema)

  
• Accuracy of EBV's


  • Individual: 55%
  • Individual + sire + dam: 60%
  • 10 progeny: 67%
  • 32 progeny: 85%
  • Individual + 10 progeny: 74%
  • Individual + 45 progeny: 90%
• As the breed is improved over time, the breed average may shift far from zero
• Consider differences between bulls available for purchase when making choices
• Commercial farmers must work with breeders who are seeking to provide genetic information
• Bull breeders must present genetic information that is directly connected with beef enterprise profit
• Breeders need to record the right information and have recording providers present it in a way that is economically relevant
• Breeders should develop relevant Indexes using Breed Plan
• Indexes


  • Maternal Index
  • Terminal Index
  • Dairy/Maternal Index
  • Export/Maternal Index
  • Hereford Prime/Maternal Index
  • Angus Pure Index
• Angus Pure Index


  Estimates the genetic differences between animals in net profitability per cow joined for a self replacing commercial Angus herd, targeting the production of grass finished steers for the AngusPure programme. Steers are assumed marketed at 525 kg live weight (280 kg carcase weight and 10 mm fat depth) at 18 months of age with a significant premium paid for marbling.

  
• Self Replacing Index


  Estimates the genetic differences between animals in net profitability per cow joined for a self replacing commercial herd, targeting the production of grass finished steers. Steers are assumed marketed at 525 kg live weight (280 kg carcase weight and 10 mm fat depth) at 16 months of age.

  
• Difference between bulls ARDO ACHILLES 120 and ARDO ACHILLES 2056 is 10kg, half of which (5kg) appears in progeny, and over 50 offspring this amounts to 250kg